Pathology Flashcards
What is inflammation?
Inflammation is the body’s process of fighting things that harm it such as infections, injuries and toxins.
What are the types of inflammation?
Acute and chronic inflammation.
What is acute inflammation?
The initial tissue reactions to injury which may last from a few hours to a few days.
What is acute inflammation mediated by?
Neutrophils
What is chronic inflammation?
The subsequent and prolonged tissue reactions to injury following acute inflammation.
What is chronic inflammation mediated by?
Macrophages and lymphocytes.
What is inflammation characterised by?
The 5 cardinal signs.
What are the 5 cardinal signs?
- Rubor (redness)2. Dalor (pain)3. Calor (heat)4. Tumor (swelling)5. Function loss
What are the 3 stages of acute inflammation?
- Increased vessel calibre - vasodilation by cytokines (bradykinin, NO, prostaglandins)2. Fluid exudate - Leaky vessel, fluid forced out3. Cellular exudate - Neutrophils become abundant
What do neutrophils do in acute inflammation?
- Margination - To edge of vessel2. Adhesion - Neutrophils bind to endothelium of vessel3. Emigration - Neutrophils move out of vessel4. Chemotaxis - phagocytosis, phagolysosome, macrophage clears debris.
What are the four outcomes of acute inflammation?
- Resolution - Tissue restored to normal2. Supportation - Pus formation3. Organisation - Granulation tissue and fibrosis.4. Progression - Excessive recurrent inflammation; becomes chronic and fibrotic tissue.
What are granulomas?
They’re aggregates of macrophages in response to chronic inflammation.
What is the significance of granuloma shape?
- Central necrosis - TB2. No central necrosis - Crohn’s, leprosy, sarcoidosis
What is the marker for granulomas?
ACE as they secrete it.
What is thrombus?
A mass of blood constituents (platelets) forming in vessels.
How does a thrombus form?
- Vasospasm2. Primary platelet plug - VWF binds to exposed collagen; platelets bind to this.3. Coagulation cascade
What is Virchow’s triad?
Three factors in the contribution of thrombosis. Only one is needed but it’s usually two or three.
What are the factors in Virchow’s triad (with examples)?
- Endothelial injury - Trauma, smoking, MI, surgery.2. Hypercoagulability - Sepsis, atherosclerosis, pregnancy, malignancy.3. Decreased blood flow - AF, immobility.
What are the different types of thrombosis?
Arterial and venous thrombi.
How does an arterial thrombus form?
Forms by atherogenesis.
How does a venous thrombus form?
Forms by venous stasis.
What are the fates of thrombi?
- Resolution - degrades2. Organisation - leaves behind scar tissue3. Embolism - fragments of thrombi break away and lodge in distal circulation
What is an embolus?
An embolus is a fragment of a thrombus which has broken off.
What are the types of emboli?
Arterial and venous.
What is an example of an arterial embolus?
A thrombus from AF embolises and lodges in the carotid artery causing an ischaemic stroke.
What is an example of a venous embolus?
A DVT thrombus embolises and lodges in the pulmonary artery causing a PE.
What is atherosclerosis?
Fatty plaque that forms in the intima and media of arteries, hardening and narrowing them over time.
What causes atherosclerosis?
Chronic inflammation and activation of the immune system in the artery wall.
What are the contents of an atherosclerotic plaque?
Lipids, smooth muscle, macrophages, platelets, fibroblasts.
What are the non-modifiable and modifiable risk factors for atherosclerosis?
Non-modifiable: age, family history, gender.Modifiable: smoking, alcohol, poor diet, low exercise, obesity, poor sleep and stress.
What is the name of the formation of a plaque?
Atherogenesis.
What are the four steps of atherogenesis?
- Endothelial injury2. Fatty streak3. Inflammatory reaction4. Fibrous cap
How does a fibrous cap in atherosclerosis cause further narrowing?
If the fibrous cap ruptures, there is continuous plug formation which occludes the lumen leading to narrowing.
What is apoptosis?
Apoptosis is non-inflammatory genetically programmed cell death without any harmful product release.
How do cells appear in apoptosis?
Cells shrink, organalles are retained, cytoplasm stays intact, chromatin is unaltered, fragmented for phagocytosis.
What are the mechanisms for apoptosis?
- Intrinsic2. Extrinsic3. Cytotoxic
What is necrosis and what causes it?
Inflammatory unprogrammed cell death due to adverse event such as infarction, burn, frostbite, infection and trauma.
How do cells appear in necrosis?
Cells burst, organelles splurge, cytoplasm is damaged, chromatin is altered, and the cell is FUCKED.
What are the different patterns of necrosis?
- Coagulative2. Liquefactive3. Caseous4. Gangrene
What is hypertrophy?
Cell gets bigger without cell division.
What is hyperplasia?
Number of cells increase via mitosis.